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Eug Wanker · Sep 28, 2006, 01:39 PM

I had bought a flashed PC GeForce 2 MX a couople of years ago hoping it would fit in the Cube, but it was a little bit too big. So I stuffed it in the cupboard and bought another GPU. However, that second GPU is now dying so I decide to do something with the video card that was too big.

I took a hacksaw it, and cut it to size. I didn't feel like moving the VRM in the Cube (which is what was in the way).

Here is a pic of where I made the cut:

Despite the fact I cut a whole bunch of traces on the board, it works perfectly, because the spot where I cut seems to be unused.

I've put the details in this PDF. It's also in my sig.

SirCastor · Sep 28, 2006, 01:45 PM

Wow. Do you have pics of it installed?

Dork. · Sep 28, 2006, 01:53 PM

Heh. You posted the picture, and I sawed it.

I'm really suprised you didn't short a power plane to a ground plane. I think you're quite lucky.

It reminds me of the time a number of years back when I was a young pup of an engineer. A research scientist was asking me all sorts of questions about a board I was supporting, and how much of the board contained functions that he needed for his work. A few days later, he said the board stopped working and requested another one. It turns out that when this Ph.D. learned that the components on one side of the board weren't needed for what he was doing, he decided to save some space in his lab by breaking the board in half, right down the middle, and discarding thw unused portion. He did, unfortunately, short out the power plane, and the Blue Smoke left the chips on the board, rendering it unusable. My boss then politely filled him in on how printed circuit boards are constructed, and why it's a bad idea to just break one in half and then power it up.

I kept the broken board, to remind myself why it's good I stopped at my MSEE.

Eug Wanker · Sep 28, 2006, 02:26 PM

Originally Posted by Dork.

Heh. You posted the picture, and I sawed it.

I'm really suprised you didn't short a power plane to a ground plane. I think you're quite lucky.

It reminds me of the time a number of years back when I was a young pup of an engineer. A research scientist was asking me all sorts of questions about a board I was supporting, and how much of the board contained functions that he needed for his work. A few days later, he said the board stopped working and requested another one. It turns out that when this Ph.D. learned that the components on one side of the board weren't needed for what he was doing, he decided to save some space in his lab by breaking the board in half, right down the middle, and discarding thw unused portion. He did, unfortunately, short out the power plane, and the Blue Smoke left the chips on the board, rendering it unusable. My boss then politely filled him in on how printed circuit boards are constructed, and why it's a bad idea to just break one in half and then power it up.

I kept the broken board, to remind myself why it's good I stopped at my MSEE.

Heh. I don't even know what that means really. Am I assume that there should be traces with power even at the periphery of the card?

Originally Posted by SirCastor

Wow. Do you have pics of it installed?

Yeah, it's in that PDF I posted, but I'll rehost the images later. The images in the blog post won't display here.

Dork. · Sep 28, 2006, 03:00 PM

Originally Posted by Eug Wanker

Heh. I don't even know what that means really. Am I assume that there should be traces with power even at the periphery of the card?

Circuit boards are made up of a number of layers, not just the top and bottom. Some of these layers contain traces, just like the top and bottom do. Most modern boards with reasonable power and speed requirements devote entire layers to power and ground. Ground, especially, is important on any card that consumes a lot of power: more power = more current = more heat when traces are small. And even thogh there might be more than one power supply for current to flow through, there's usually only one ground. (Except when there's not, but that's a different discussion.

), So, instead of routing power and ground as separate small traces to all the IC's which would have to get larger as they feed into (or out of) more IC's, there are entire power and ground layers which each IC connects to, and are large enough to handle all the current.

There are reasons why a designer would not extend the power and ground planes throughout the entire board area, though. You might have just gotten lucky, and the part you hacked off happened to not have the power and ground planes in it. My Ph. D. friend was in trouble because he broke the board in half right down the middle, where of course any small short between power and ground planes is bad.

I'm not a board designer, though. If I showed my explanation to the guy down the hall from me, he's probably have a thing or two to say about it.

Eug · Sep 28, 2006, 03:09 PM

Yeah, I was worried there might be some other layers I couldn't see when I sawed it, but I must admit I was thinking not so much about power vs ground, but other traces I couldn't see. IOW, I didn't know any better.

BTW, should I seal it somehow? I'm guessing nail polish may not be so good, because of the solvent.

Oh and I intend this only to be a temporary thing. I'm getting a new video card that will fit properly. I just didn't want to have to deal with the lack of QE in the meantime.

Dork. · Sep 28, 2006, 03:26 PM

The thing I'd worry about most is traces getting shorted if you happen to be putting something metal near the edge. From the PDF, it looks like you may not have to worry about that. Maybe you could put some electrical tape on the edge if you like, but make sure not to out it on too tight. There might be some "flaky" layers what work just fine right now, but might break depending on how much pressure is put on that end.

Now that I've had a good look at your PDF and saw where you cut, it makes a little more sense, as that top corner was probably just used as a place to put that header (which I hopy you don't need anymore! :lol"). The actual design may not have even used that corner of the board, but the manufacturer probably saw no need to cut the size of the board there.

Still, that's something I wouldn't do. I've taken a dremel to PC and TiVo cases before, but never a circuit board....

Eug Wanker · Sep 28, 2006, 11:22 PM

I'll put some electrical tape on it. This will hold me over until my Radeon 9200 arrives.

Wow. Do you have pics of it installed?

Pix!

macgyvr64 · Oct 11, 2006, 10:51 PM

I can't believe that worked... That shouldn't have worked...

Eug Wanker · Oct 12, 2006, 09:43 AM

I ended up taking it out. The video card and the Cube still work fine, but the card generates too much heat. (In fact, I think that's why my previous GeForce 2 MX was failing.) It makes my Cube a little too toasty for my tastes, and I don't want to put a fan on the card. So I'm stuck without having Quartz Extreme again.

Hopefully my Radeon 9200 will arrive soon. I may also be able to get a GeForce 6200 (with Core Image support). Both are fanless and are supposed to be cooler than the GeForce 2 MX.

BigBadBiologist · Oct 12, 2006, 02:57 PM

Yeah, it looks like the only thing that you would have screwed up is the VESA connector which I don't think any Mac has ever used. Cool hack!

dru · Oct 14, 2006, 04:44 PM

A literal hack! Crazy.